1. Field of the Invention
The present invention relates to novel oxime derivatives of 5-formylpyridyl imidazolinone compounds, the method of using said compounds as herbicidal agents and the methods for preparing said compounds.
2. Description of the Related Art
By way of background, U.S. Pat. No. 4,798,619 discloses 2-(2-imidazolin-2-yl) pyridine and quinoline compounds of the general formula: ##STR2## wherein Y and Z each represent members selected from the group consisting of hydrogen, halogen, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.4 hydroxyloweralkyl, C.sub.1 -C.sub.6 alkoxy, C.sub.1 -C.sub.4 alkylthio, phenoxy, C.sub.1 -C.sub.4 haloalkyl, nitro, cyano, C.sub.1 -C.sub.4 alkylamino, diloweralkylamino, C.sub.1 -C.sub.4 alkylsulfonyl group or phenyl optionally substituted with one C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or halogen; and when taken together, Y and Z may form a ring in which YZ are represented by the structure: --(CH.sub.2).sub.n --, where n is an integer of 3 or 4, provided that X is hydrogen; or ##STR3##
Japanese Patent Application No. J62174-069-A discloses pyridine compounds of the general formula: ##STR4## wherein X may be hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxymethyl, C.sub.1 -C.sub.4 alkylthiomethyl, C.sub.1 -C.sub.4 haloalkyl, C.sub.1 -C.sub.4 alkylsulfonylmethyl, benzyl or an optionally substituted phenyl or pyridyl group and Y is oxygen, sulfur, monosubstituted nitrogen (in which the substituent is C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 alkoxycarbonylamino or an optionally substituted phenyl or pyridyl group) or disubstituted carbon. The pyridyloxime, 5-acetyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-6-methylnicotini c acid, pyridine-5-(O-ethyloxime), is given as an example. However, in practical use, the herbicide activity of this compound is not satisfactory against many commonly encountered weed species. Further, the tolerance of this compound in crop species limits its use at high rates.